Monitoring thickness uniformity

ABSTRACT

Devices, methods, and systems for monitoring thickness uniformity are described herein. One system includes a transmitter configured to transmit a signal through a portion of a material while the material is moving, an attenuator configured to absorb a first portion of the transmitted signal, a reflector configured to reflect a second portion of the transmitted signal, a receiver configured to receive the reflected signal, and a computing device configured to determine a thickness of the portion of the material based on a time delay between the transmission of the signal and the reception of the reflected signal

PRIORITY INFORMATION

This application claims priority to U.S. Provisional Patent Application62/236,227, filed Oct. 2, 2015, U.S. Provisional Patent Application62/236,237, filed Oct. 2, 2015, and U.S. Provisional Patent Application62/236,218, filed Oct. 2, 2015, the entire specifications of which areincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to devices, methods, and systems formonitoring thickness uniformity.

BACKGROUND

A uniform thickness of a material may be desirable in various contexts.Such contexts can include, for example, manufacturing and/or continuousline production of materials such as insulation, plastic sheets, roofingshingles, nonwoven filter material, rubber-based products (e.g., rubberwith embedded magnetic material), and/or thickness measuring of tiresand/or belts (e.g., conveyor belts, transmission belts, etc.), amongothers.

For instance, conveyor belts are used in industries such as mining,power generation, and agriculture, among others. Due to usage and/oraccidents, conveyor belts can be damaged by wear or tearing.

Both excessive wear and belt tearing can result in unscheduled workstoppages. Because many industries using conveyor belts are located inremote settings, and because of the large size of their machinery,repairing a conveyor belt can take hours or days. Additionally, the leadtime for acquiring a new conveyor belt can be excessive (e.g., sixmonths). Losses for industries due to interrupted production fromdamaged belts may be immense.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross-sectional view of a system for monitoringconveyor belt thickness in accordance with one or more embodiments ofthe present disclosure.

FIG. 2 illustrates a cross-sectional view of a system for monitoringconveyor belt thickness in accordance with one or more embodiments ofthe present disclosure.

FIG. 3 illustrates a different cross-sectional view of a portion of thesystem illustrated in FIG. 1 in accordance with one or more embodimentsof the present disclosure.

FIG. 4 illustrates a top-down view of a portion of the systemillustrated in FIG. 1 in accordance with one or more embodiments of thepresent disclosure.

FIG. 5 illustrates a perspective view of a system for monitoringconveyor belt thickness in accordance with one or more embodiments ofthe present disclosure.

FIG. 6 illustrates a cross-sectional view of a system for monitoringconveyor belt thickness in accordance with one or more embodiments ofthe present disclosure.

FIG. 7 illustrates a computing device for monitoring conveyor beltthickness in accordance with one or more embodiments of the presentdisclosure.

DETAILED DESCRIPTION

Devices, methods, and systems for monitoring conveyor belt thickness aredescribed herein. Embodiments of the present disclosure can detectexcessive wear on a conveyor belt and estimate the remaining life of thebelt (e.g., time until failure). Thus, maintenance and/or replacement ofthe belt can be scheduled before failure such that the productionprocess is minimally interrupted.

Typical damage to a conveyor belt can include parabolic-shaped wear nearthe center of the belt, groove-shaped wear near the belt skirts, damageto the belt splice, delamination of belt layer(s), and/or hole(s) in thebelt. Embodiments of the present disclosure could detect some of thesetypes of damage and provide advance notice to maintenance personnel.

Embodiments herein can be installed in existing conveyor belt systemswithout changing the operation of the system. In addition to conveyorbelts, embodiments herein can be applied in other contexts such asmanufacturing, for instance, where a monitoring a thickness of amaterial may be desired. Such contexts can include, for example,continuous line production of insulation, plastic sheets, roofingshingles, nonwoven filter material, rubber-based products (e.g., rubberwith embedded magnetic material), and/or thickness measuring of tiresand/or other belts (e.g., transmission belts). Thus, it is noted thatwhile the example of conveyor belts is used herein, such usage is notintended to be limiting.

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof. The drawings show by wayof illustration how one or more embodiments of the disclosure may bepracticed.

These embodiments are described in sufficient detail to enable those ofordinary skill in the art to practice one or more embodiments of thisdisclosure. It is to be understood that other embodiments may beutilized and that process changes may be made without departing from thescope of the present disclosure.

As will be appreciated, elements shown in the various embodiments hereincan be added, exchanged, combined, and/or eliminated so as to provide anumber of additional embodiments of the present disclosure. Theproportion and the relative scale of the elements provided in thefigures are intended to illustrate the embodiments of the presentdisclosure, and should not be taken in a limiting sense.

The figures herein follow a numbering convention in which the firstdigit or digits correspond to the drawing figure number and theremaining digits identify an element or component in the drawing.Similar elements or components between different figures may beidentified by the use of similar digits.

FIG. 1 illustrates a cross-sectional view of a system 100 for monitoringconveyor belt thickness in accordance with one or more embodiments ofthe present disclosure. As shown in FIG. 1, system 100 includes atransmitter (e.g., transmitting antenna) 102, a reflector 108, anattenuator 110, and a receiver (e.g., receiving antenna) 112. As shown,the transmitter 102, the attenuator 110 and the receiver 112 can bepositioned on a first side of a conveyor belt (hereinafter “belt”) 106,and the reflector 108 can be positioned on a second, opposing side ofthe belt 106.

The transmitter 102 can be a transmitting antenna, for instance, and canbe configured to transmit a pulsed or continuous wave radar signal. Thetransmitter 102 is not limited to a particular type of transmitter. Insome embodiments, the transmitter 102 can be a 10 GHz transmitter,though embodiments of the present disclosure are not so limited. Forexample, in some embodiments, frequencies between 2.4 to 77 GHz can beused. Higher frequencies may result in improved spatial and/or thicknessresolution, but may be limited by attenuation with thicker materials.The transmitter 102 can be positioned at a 45-degree angle with respectto the belt 106 and/or the reflector 108, though embodiments of thepresent disclosure are not so limited.

The reflector 108 can include a reflective surface (e.g., a metallicsurface and/or fine metal mesh), though embodiments herein to not limitthe reflector to a particular type of reflector. The reflector 108 canfocus and/or reflect a radar signal transmitted by the transmitter 102,for instance.

The attenuator 110 can be a device configured to attenuate (e.g.,absorb) a radar signal, for instance, and can include a foam material,though embodiments of the present disclosure are not so limited. Thereceiver 112 can be a receiving antenna, for instance, configured toreceive a radar signal. The receiver 112 is not limited to a particulartype of receiver.

As shown in FIG. 1, the transmitter 102 can transmit a radar signal(hereinafter “signal”) 104. The signal can be directed towards the belt106 and towards the reflector 108 (e.g., through the belt 106). Aportion of the signal 104 may be reflected before reaching the reflector108. As shown a first portion 104-1 of the signal 104 can reflect off ofa surface (e.g., a top surface) of the belt 104. A second portion 104-2of the signal 104 can reflect off of another (e.g., bottom) surface ofthe belt 106.

The attenuator 110 can be positioned to attenuate (e.g., block) thereflected signals 104-1 and/or 104-2 such that they are not received bythe receiver 112. Additionally, the attenuator 110 can attenuate directinterference (e.g., non-reflected interference) between the transmitter102 and the receiver 112.

The signal 104 can pass through the belt 106 and reflect off of thereflector 108. Thereafter, the signal (shown as reflected signal 104-3)can pass back through the belt 106 and then be received by the receiver112. Thus, the signal 104 penetrates the belt 106 twice: once before thereflection and once after the reflection. Each time the signal 104penetrates the belt 106 its velocity is reduced. The reduction invelocity can be proportional to a square root of a dielectric constant(e.g., permittivity) of the belt 106. Additionally, the signal 104 canbe attenuated proportional to an exponential function of the thicknessof the belt 106.

Thus, the thickness of the belt 106 can be determined from a time delaybetween the transmitted and received signal 104 compared to a time delayof a reference signal obtained without penetration of the belt. Thoughnot shown in FIG. 1 so as not to obscure embodiments of the presentdisclosure, a portion of the reflector 108 can extend beyond an outeredge of the belt 106. The reference signal can be obtained bytransmitting the signal 104 onto the portion of the reflector 108 thatextends beyond the edge of the belt 106 and receiving the referencesignal by the receiver 112. In a similar manner, the thickness of thebelt 106 can be determined from the attenuation of the received signalas compared to the reference signal that does not pass through the belt106.

Since the reference RF beam that is travelling over the same distancebut without the belt is required for calibration that measurement can becarried out using another receiver that is located beyond the edge ofthe conveyor belt 106 (e.g., such that the conveyor belt 106 is notbetween the other receiver and the transmitter 102). Beyond the edge ofthe belt the other antenna may not have the belt 106 present in the RFbeam path and could be used for the calibration of the dielectricconstant. It is noted that a sample portion of the belt 106 (e.g., aremnant, scrap, test sample, etc.) can be placed between the otherantenna and the transmitter 102, though is not shown in FIG. 1 so as notto obscure embodiments of the present disclosure. The calibrations usingthe sample portion of the conveyor belt 106 and/or antennas can becarried out periodically or on a scheduled basis, for instance, todetermine a dielectric constant of the belt 106 at differenttemperatures and/or other conditions (e.g., humidity levels, atmosphericconditions, etc.).

Embodiments of the present disclosure can calibrate the system 100 tothe belt 106 using a portion of the belt 106 proximal to an edge of thebelt 106. Such a portion may, for instance, experience reduced wear thana medial portion of the belt 106 and may thus act as a suitable samplefor calibration purposes.

It is noted that the conveyor belt 106 is not intended to be limited toa particular type of conveyor belt. In addition, it is noted that whilethe example of a conveyor belt is used herein for the purposes ofillustration, embodiments of the present disclosure can monitorthicknesses of objects other than conveyor belts, as previouslydiscussed.

The thickness of the belt 106 can be determined as the belt 106 moves,for instance. In some embodiments, the system 100 (and the system 213,discussed below in connection with FIG. 2) can be affixed to a supportdevice (not shown so as not to obscure embodiments of the presentdisclosure). The support device can be a frame, for instance, or otherdevice that maintains a fixed position of the transmitter 102, thereceiver 112, the attenuator 110, and/or the reflector 108. The supportdevice can be installed such that the system 100 can be installedwithout interruption of the operation and/or movement of the belt 106.

FIG. 2 illustrates a cross-sectional view of another system 213 formonitoring conveyor belt thickness in accordance with one or moreembodiments of the present disclosure. In a manner analogous to thesystem 100 discussed previously, the system 213 includes a transmitter202, an attenuator 210, a reflector 208, and a receiver 212. Thetransmitter 202 can be positioned at a 60-degree angle with respect tothe belt 206, though embodiments of the present disclosure are not solimited.

In some embodiments, the system 213 can be utilized in instances where abelt 206 includes reinforcement 207. The reinforcement 207 can include ametal layer (e.g., steel) and/or one or more metal cables therein. If,for instance, the belt 207 includes a plurality of metal cables spacedsufficiently close together such that their spacing is significantlyexceeded (e.g., exceeded by a factor of 5) by a wavelength of the radarsignal in the belt 206 (e.g., 1 centimeter for a 10 GHz signal anddielectric constant of 9), then the cables can reflect the signal.

As shown in FIG. 2, the transmitter 202 can transmit a signal 204. Thesignal can be directed towards the belt 206. A portion of the signal 204may be reflected before reaching the reinforcement 207. As shown a firstportion 204-1 of the signal 204 can reflect off of a surface (e.g., atop surface) of the belt 206.

The attenuator 210 can be positioned to attenuate (e.g., block) thereflected signal 204-1 such that it is not received by the receiver 212.Additionally, the attenuator 210 can attenuate direct interference(e.g., non-reflected interference) between the transmitter 202 and thereceiver 212.

The signal 204 can pass through a top portion of the belt 206 andreflect off of the reinforcement 207. Thereafter, the signal (shown asreflected signal 204-2) can pass back through the top portion of thebelt 206, reflect off of the reflector 208, and then be received by thereceiver 212. In a manner analogous to that previously discussed, whenthe signal 204 penetrates the top portion of the belt 206 its velocityis reduced. The reduction in velocity can be proportional to a squareroot of a dielectric constant (e.g., permittivity) of the belt 206.Additionally, the signal 204 can be attenuated proportional to anexponential function of the thickness of the belt 206.

Thus, the thickness of the top portion of the belt 206 can be determinedfrom a time delay between the transmitted and received signal 204compared to a time delay of a reference signal obtained withoutpenetration of the belt 206. Though not shown in FIG. 2 so as not toobscure embodiments of the present disclosure, a portion of thereinforcement 207 can extend beyond an outer edge of the belt 206. Insome embodiments, a reference reflector can be positioned beyond anouter edge of the belt 206 at substantially a same distance from thetransmitter 102 as the reinforcement 207. The reference signal can beobtained by transmitting the signal 204 onto the portion of thereinforcement 207 that extends beyond the edge of the belt 206 (or thereference reflector) and receiving the reference signal by the receiver112. In a similar manner, the thickness of the belt 206 can bedetermined from the attenuation of the received signal as compared tothe reference signal that does not pass through the belt 206.

FIG. 3 illustrates a different cross-sectional view of a portion of thesystem 100 illustrated in FIG. 1 (illustrated as system 300 in FIG. 3).The system 300 can be analogous to the system 100; for instance, thesystem 300 includes a transmitter 302 and a reflector 308. System 300can additionally include a receiver and/or an attenuator though suchcomponents are not illustrated in FIG. 3 so as not to obscureembodiments of the present disclosure.

As shown in FIG. 3, the reflector 308 can have a concave configuration(e.g., shape). A radius of curvature of the reflector 308 can allow theredirection of a signal 304 towards a receiver (not shown) and can focusthe reflected signal. If, for instance, the signal is not focused, someof the reflected signal (e.g., a periphery of the reflected signal) maynot be collected by the receiver and thus the thickness of the belt 306penetrated by that portion of the reflected signal would not bemeasured.

As previously discussed, and as shown in FIG. 3, the reflector 308 canextend beyond the edge(s) of the belt 306. The signal 304 can bedirected towards the reflector 308 beyond the edge of the belt 306striking the reflector 308 at a reference footprint 314. The signal 304can reflect off of the reflector 308 at the reference footprint 314towards the receiver.

FIG. 4 illustrates a top-down view of a portion of the system 100illustrated in FIG. 1 (illustrated as system 400 in FIG. 4). The system400 can be analogous to the system 100 and the system 300; for instance,the system 400 includes a transmitter 402, a receiver 412, and areflector 408. System 400 can additionally include an attenuator, thoughnot illustrated in FIG. 4 so as not to obscure embodiments of thepresent disclosure.

In accordance with one or more embodiments of the present disclosure,the transmitter 402 can direct a signal 404 towards the reflector 408through the belt 406. As shown in FIG. 4, the signal 404 penetrates thebelt 406 at an area defined by an entry footprint 416. Subsequently, thesignal 404 reflects off of the reflector 408 and passes back through thebelt 406 at an area defined by an exit footprint 418. The reflectedsignal (shown as reflected signal 404-3) can then be received by thereceiver 412.

It is noted that the entry footprint 416 and the exit footprint 418 areseparated by a particular distance of the belt 406. The distance can bedefined based on a speed of the belt and/or an angle of the signal. Sucha distance can be selected such that a portion of the signal 404reflected from a top surface of the belt 406 is prevented from beingreceived by the receiver 412 and corrupting thickness determination(s).

The process of steering the signal 404 to a particular entry footprinton the belt 406 can be carried out across the width of the belt 406. Asshown by a plurality of entry footprints on the belt 406, and by thereference footprint 414, an entire width of the belt can be scanned.Such scanning be continued in a cyclical manner (e.g., at approximately100 Hertz). That is, the belt 406 can be “swept” from one side to anopposing side by the signal (and back again) in a cyclical manner. Asthe belt 406 travels, the sweeping of the signal can yield a triangular(e.g., zig-zag) pattern along the belt 406 where its thickness has beendetermined. In some embodiments, each entry footprint can havedimensions of approximately 8.8 by 44 centimeters, though embodiments ofthe present disclosure are not so limited.

In some embodiments, a mapping of the thickness of a conveyor belt canbe created (e.g., along an entire length and width of the belt). Forexample, a speed of the belt movement can be determined and/or known,and a particular portion (e.g., “beginning”) of the belt can bedetermined and/or registered. In an example, a set of metal strips canbe embedded in a bottom surface of the belt at a particular location.Radar systems in accordance with one or more embodiments of the presentdisclosure can determine that less energy is transmitted through thebelt at that location and associate that location with a “startingpoint” for mapping the thickness of the belt along its length. Themapping of the belt can be stored in memory, for instance, and can beused to generate a graphical rendering of the thickness of the entirebelt.

FIG. 5 illustrates a perspective view of a system 520 for monitoringconveyor belt thickness in accordance with one or more embodiments ofthe present disclosure. As shown in FIG. 5, system 520 includes atransmitter 502 and an antenna array 512 positioned on opposing sides ofa conveyor belt 506. In the example illustrated in FIG. 5, the conveyorbelt has a width of 2 meters, though embodiments herein are not limitedto a particular width and/or thickness of conveyor belt. The conveyorbelt 506 is not intended to be limited to a particular type of conveyorbelt. In addition, it is noted that while the example of a conveyor beltis used herein for the purposes of illustration, embodiments of thepresent disclosure can monitor thicknesses of objects other thanconveyor belts, as previously discussed.

The transmitter 502 can be a phased array antenna, for instance, havinga plurality of radiating elements with a phase shifter. In someembodiments, the transmitter 502 can be a 10 GHz transmitter, thoughembodiments of the present disclosure are not so limited. For example,in some embodiments, frequencies between 2.4 to 77 GHz can be used.Higher frequencies may result in improved spatial and/or thicknessresolution, but may be limited by attenuation with thicker materials.

A plurality of beams can be formed by shifting the phase of a signalemitted from each radiating element such that the beams are directed ina desired direction. The beams can be radio frequency (RF) beams, forinstance, though embodiments of the present disclosure are not solimited. The cumulative paths of the plurality of beams are representedin FIG. 5 by the scan plane 508. Each beam can have a particulardivergence angle (e.g., two degrees). The transmitter 502 can bepositioned at a particular distance from the conveyor belt 506. In someembodiments, the distance is 12 inches, though embodiments herein arenot so limited.

The antenna array 512 can include a plurality of receiving antennas. Inthe example illustrated in FIG. 5, the antenna array 512 includes 19antennas, though embodiments herein are not so limited. Each of theantennas of the antenna array 512 can be located at a same distance froma source of the beam (i.e., the transmitter 502). That is, the antennasof the antenna array 512 can be positioned in a semicirculararrangement.

In accordance with one or more embodiments of the present disclosure,the transmitter 502 can direct a beam towards an antenna of the antennaarray 512. For example, the transmitter 502 can direct an RF beamtowards the antenna 512-2 of the antenna array 512. As the beam passesthrough the conveyor belt 506, the RF wave is slowed down and issubsequently received by the antenna 512-2. The operation of the system520 is based on the slowing of the RF wave in the belt material beinginversely proportional to the square root of the dielectric constant(e.g., permittivity) of the material. That is, the wave arrives at theantenna 512-2 with more phase delay than it would if it did not passthrough the conveyor belt 506. Further, the slowing down of the RF beamcauses a phase shift with respect to the RF beam transmitted over thesame distance but without the belt present; the level of phase delay canbe proportional to a thickness of the conveyor belt 506.

In some embodiments, a distance between the transmitter 502 and theantenna array 512 is fixed and is known. In some embodiments, adielectric constant of the conveyor belt 506 is known.

To determine an unknown dielectric constant of the conveyor belt 506(e.g., to calibrate the system 520 to the conveyor belt 506),embodiments of the present disclosure can insert a portion of theconveyor belt 506 having a known thickness into the scan plan 508. Thephase delay resulting from the beam passing through the conveyor belt506 can be used to determine the dielectric constant of the materialcomprising the conveyor belt 506. That is, if the distance between thetransmitter 502 and the antenna array 512, as well as the dielectricconstant, do not change, the determined phase delay can be proportional,and thus converted, into the belt thickness for another portion of theconveyor belt 506.

Since the reference RF beam that is travelling over the same distancebut without the belt is required for calibration that measurement can becarried out using an antenna of the antenna array 504 that is locatedbeyond the edge of the conveyor belt 506 (e.g., such that the conveyorbelt 506 is not between the antenna and the transmitter 502). In theexample illustrated in FIG. 5, that antenna is illustrated as antenna512-5. Beyond the other edge of the belt the antenna 512-1 does not havethe belt present in the RF beam path and could be used for thecalibration of the dielectric constant. It is noted that a sampleportion of the conveyor belt 506 (e.g., a remnant, scrap, test sample,etc.) can be placed between the antenna 512-1 and the transmitter 502,though is not shown in FIG. 5 so as not to obscure embodiments of thepresent disclosure. The calibrations using the sample portion of theconveyor belt, 506 antenna 512-6, and antenna 512-1 can be carried outperiodically or on a scheduled basis, for instance, to determine adielectric constant of the conveyor belt 506 at different temperaturesand/or other conditions (e.g., humidity levels, atmospheric conditions,etc.).

Embodiments of the present disclosure can calibrate the system 520 tothe conveyor belt 506 using a portion of the conveyor belt 506 proximalto an edge of the conveyor belt 506. Such a portion may, for instance,experience reduced wear than a medial portion of the conveyor belt 506and may thus act as a suitable sample for calibration purposes.

The thickness of the conveyor belt 506 can be determined as the conveyorbelt 506 moves, for instance. In some embodiments, the beam from thetransmitter 502 can be directed at different antennas of the antennaarray 512 in a particular sequence. That is, a thickness of the conveyorbelt 506 can be determined across its entire width by sweeping the beamacross the antenna array 512.

For example, the transmitter 502 can direct the beam at a first antenna(e.g., antenna 512-2) at a first time. While the beam is directed at thefirst antenna, adjacent antennas (e.g., antenna 512-1 and/or 512-3) canbe deactivated (e.g., switched off). Deactivating additional antennascan allow embodiments of the present disclosure to ensure that only thebeam passing through a desired portion of the conveyor belt 506 isreceived and read by the antenna without contributions from otherreceiving antennas. Subsequently, the transmitter 502 can direct thebeam at a second antenna (e.g., antenna 512-3) adjacent to the firstantenna. While the beam is directed at the second antenna, antennasadjacent to the second antenna (e.g., antenna 512-2 and/or antenna512-4) can be deactivated. It is noted that antennas in addition toadjacent antennas can also be deactivated.

The process of activating sequential antennas of the antenna array 512can be continued in a cyclical manner (e.g., at approximately 100Hertz). That is, the conveyor belt 506 can be “swept” from one side toan opposing side by the beam (and back again) in a cyclical manner. Asthe conveyor belt 506 travels, the sweeping of the beam can yield atriangular (e.g., zig-zag) pattern along the conveyor belt 506 where itsthickness has been determined.

FIG. 6 illustrates a cross-sectional view of another system 622 formonitoring conveyor belt thickness in accordance with one or moreembodiments of the present disclosure. The system 622 includes aplurality of transmitters (i.e., a transmitter 602-1, a transmitter602-2, a transmitter 602-3, a transmitter 602-4, a transmitter 602-5, atransmitter 602-6, a transmitter 602-7, a transmitter 602-8, and atransmitter 602-9, collectively referred to as “transmitters 602”). Thetransmitters 602 can be arranged in a substantially linear arrangement.The transmitters 602 can be configured to direct RF beams in asubstantially equivalent direction.

The system 610 can include a plurality of antennas (i.e., an antenna612-1, an antenna 612-2, an antenna 612-3, an antenna 612-4, an antenna612-5, an antenna 612-6, an antenna 612-7, an antenna 612-8, and anantenna 612-9, collectively referred to as “antennas 612” and/or“antenna array 612”). The antennas 612 can be positioned on a side of aconveyor belt 606 opposing the transmitters 602. The antennas 612 can bearranged in a substantially linear arrangement. The antennas 612 can beconfigured to receive RF beams from a substantially equivalentdirection.

As shown in FIG. 6, the antennas 612 and the transmitters 602 can bepositioned such that they oppose each other. Each antenna can beassociated with a respective transmitter; that is, each antenna can beconfigured to receive a beam from a single transmitter. For example, theantenna 612-4 can be configured to receive a beam from the transmitter602-4. In some embodiments, more than one antenna can be configured toreceive a beam from a single transmitter. Though nine antennas 612 andnine transmitters 602 are illustrated in FIG. 6, embodiments of thepresent disclosure are not limited to particular numbers of antennas 612and/or transmitters 602.

In some embodiments, the antennas 612 and/or the transmitters 602 can beaffixed to a support device (not shown so as not to obscure embodimentsof the present disclosure). The support device can be a frame, forinstance, or other device that maintains a fixed position of theantennas 612 and/or the transmitters 602. The support device can beinstalled such that the antennas 612 and the transmitters 602 can beplaced on opposing sides of the conveyor belt 606 without interruptionof the operation and/or movement of the conveyor belt 606.

Each beam directed towards an antenna by a respective transmitter of thesystem 610 can have a particular divergence angle (e.g., ten degrees).The transmitters 602 and receivers 612 can be positioned at a particulardistance from the conveyor belt 606. In some embodiments, thetransmitter distance is 12 inches and receiver distance is 5 inches,though embodiments herein are not so limited.

Each of the antennas 612 can be located at a same distance from arespective one of the transmitters 602. For example, the antenna 612-6can be positioned a same distance from the transmitter 602-6 as theantenna 612-9 is from the transmitter 602-9.

In a manner analogous to that previously discussed, each of thetransmitters 602 can direct a beam towards its counterpart antenna ofthe plurality of antennas 612. As the beam passes through the conveyorbelt 606, the RF wave is slowed down and is received by the antenna. Theoperation of the system 622 is based on the slowing of the RF wave inthe belt material being inversely proportional to the square root of thedielectric constant (e.g., permittivity) of the material. That is, thewave arrives at the antennas 612 with more phase delay than it would ifit did not pass through the conveyor belt 606. Further, the level ofphase delay can be proportional to a thickness of the conveyor belt 606.

As previously discussed, a distance between the transmitters 602 and theantennas 612 can be fixed and known. In some embodiments, a dielectricconstant of the conveyor belt may be 606 is known.

The system 622 can allow the determination of a dielectric constant ofthe conveyor belt 606 and/or distance between antennas 602 and 612 in amanner analogous to that previously discussed in connection with FIG. 5.For instance, a portion (e.g., a sample portion) 606-1 of the conveyorbelt 606 having a known thickness can be inserted between an antenna anda transmitter of the system 622 beyond the edge of the conveyor belt606, shown in FIG. 6 as the antenna 612-1 and the transmitter 602-1. Thephase delay resulting from the beam directed by the transmitter 602-1passing through the conveyor belt 606 can be used to determine thedielectric constant of the material comprising the conveyor belt 606.That is, if the distance between the transmitter 602-1 and the antenna612-1, as well as the dielectric constant, do not change, the determinedphase delay can be proportional, and thus converted, into the beltthickness for another portion of the conveyor belt 606. In someembodiments, the distance between the transmitters 602 and the antennas612 can be determined by the antenna 612-9 and the transmitter 602-9.

The calibration using the portion 606-1 of the conveyor belt 606 can becarried out periodically or on a scheduled basis, for instance, todetermine a dielectric constant of the conveyor belt 606 at differenttemperatures and/or other conditions (e.g., humidity levels, atmosphericconditions, etc.).

Embodiments of the present disclosure can calibrate the system 610 tothe conveyor belt 606 using a portion of the conveyor belt 606 proximalto an edge of the conveyor belt 606. Such a portion may, for instance,experience reduced wear than a medial portion of the conveyor belt 606and may thus act as a suitable sample for calibration purposes. Forexample, such a portion may be a portion between the transmitter 602-8and the antenna 612-8.

In some embodiments, an antenna of the antennas 612 and anothertransmitter of the transmitters 602 located beyond the edge of theconveyor belt 606 (shown as the antenna 612-9 and the transmitter 602-9)can be used to determine the reference distance between transmitters 602and antennas 612. In such embodiments, there may not be a sample portion606-1 of the conveyor belt 606 between the antenna 612-9 and thetransmitter 602-9. Calibration of the system 610 with respect to thedistance between the antennas and transmitters can allow increasedaccuracy in the face of changing temperature and/or weather conditions,for instance.

The thickness of the conveyor belt 606 can be determined as the conveyorbelt 606 moves, for instance. In some embodiments, the transmitters maybe individually activated at different times according to a particularsequence. That is, a thickness of the conveyor belt 606 can bedetermined across its entire width by sequentially activating one of thetransmitters 602 at a time.

For example, a first transmitter, such as the transmitter 602-2, candirect a beam at a corresponding antenna, the antenna 612-2, at a firsttime. While the beam from the transmitter 602-2 is directed at theantenna 612-2, adjacent antennas (e.g., antenna 612-1 and/or 612-3)and/or adjacent transmitters (e.g., transmitter 602-1 and/or 602-3) canbe deactivated (e.g., switched off). Deactivating additional antennasand/or transmitters can allow embodiments of the present disclosure toensure that only the beam passing through a desired portion of theconveyor belt 606 is received and read by a corresponding antenna.Subsequently, a second transmitter, such as the transmitter 602-3, candirect a beam at a corresponding antenna, the antenna 612-3, adjacent tothe first antenna. While the beam is directed at the second antenna,antennas adjacent to the second antenna (i.e., antenna 612-2 and/orantenna 612-4) and/or transmitters adjacent to the second transmitter(i.e., transmitter 602-2 and/or transmitter 612-4) can be deactivated.It is noted that antennas and/or transmitters, in addition to adjacentantennas and/or transmitters, can also be deactivated.

The process of activating sequential antennas 612 and/or transmitters602 can be continued in a cyclical manner (e.g., at approximately 100Hertz). That is, the conveyor belt 606 can be “swept” from one side toan opposing side (and back again) by substantially parallel beams thatare substantially orthogonal to the conveyor belt 606 in a cyclicalmanner. As the conveyor belt 606 travels, the areas where the thicknessof the conveyor belt 606 was determined can yield a sinusoidal pattern.

FIG. 7 illustrates a computing device 724 for monitoring conveyor beltthickness in accordance with one or more embodiments of the presentdisclosure. The computing device 724 can be, for example, a handheldnetwork analyzer, laptop computer, desktop computer, or a mobile device(e.g., a mobile phone, a personal digital assistant, etc.), among othertypes of computing devices.

As shown in FIG. 3, the computing device 314 includes a memory 726 and aprocessor 728 coupled to memory 726. The memory 726 can be any type ofstorage medium that can be accessed by processor 728 to perform variousexamples of the present disclosure. For example, the memory 726 can be anon-transitory computer readable medium having computer readableinstructions (e.g., computer program instructions) stored thereon thatare executable by processor the 728 to control the operation of one ormore transmitters and/or receivers in accordance with one or moreembodiments of the present disclosure.

The memory 726 can be volatile or nonvolatile memory. The memory 726 canalso be removable (e.g., portable) memory, or non-removable (e.g.,internal) memory. For example, the memory 726 can be random accessmemory (RAM) (e.g., dynamic random access memory (DRAM) and/or phasechange random access memory (PCRAM)), read-only memory (ROM) (e.g.,electrically erasable programmable read-only memory (EEPROM) and/orcompact-disc read-only memory (CD-ROM)), flash memory, a laser disc, adigital versatile disc (DVD) or other optical disk storage, and/or amagnetic medium such as magnetic cassettes, tapes, or disks, among othertypes of memory.

Further, although the memory 726 is illustrated as being located in thecomputing device 724, embodiments of the present disclosure are not solimited. For example, the memory 726 can also be located internal toanother computing resource (e.g., enabling computer readableinstructions to be downloaded over the Internet or another wired orwireless connection).

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art will appreciate that anyarrangement calculated to achieve the same techniques can be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments of thedisclosure.

It is to be understood that the above description has been made in anillustrative fashion, and not a restrictive one. Combination of theabove embodiments, and other embodiments not specifically describedherein will be apparent to those of skill in the art upon reviewing theabove description.

The scope of the various embodiments of the disclosure includes anyother applications in which the above structures and methods are used.Therefore, the scope of various embodiments of the disclosure should bedetermined with reference to the appended claims, along with the fullrange of equivalents to which such claims are entitled.

In the foregoing Detailed Description, various features are groupedtogether in example embodiments illustrated in the figures for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the embodiments of thedisclosure require more features than are expressly recited in eachclaim.

Rather, as the following claims reflect, inventive subject matter liesin less than all features of a single disclosed embodiment. Thus, thefollowing claims are hereby incorporated into the Detailed Description,with each claim standing on its own as a separate embodiment.

What is claimed:
 1. A system for monitoring thickness uniformity,comprising: a transmitter configured to transmit a signal through aportion of a material while the material is moving; an attenuatorconfigured to absorb a first portion of the transmitted signal; areflector configured to reflect a second portion of the transmittedsignal; a receiver configured to receive the reflected signal; and acomputing device configured to determine a thickness of the portion ofthe material based on a time delay between the transmission of thesignal and the reception of the reflected signal.
 2. The system of claim1, wherein the material is a conveyor belt.
 3. The system of claim 1,wherein the transmitter and the reflector are located on opposing sidesof the portion of the material.
 4. The system of claim 1, wherein thetransmitter and the reflector are located on a same side of the portionof the material.
 5. The system of claim 1, wherein the first portion ofthe transmitted signal corresponds to a portion of the transmittedsignal reflected towards the attenuator by a surface of the material. 6.The system of claim 1, wherein the computing device is configured todetermine the thickness of the material based on: the time delay betweenthe transmission of the signal and the reception of the reflectedsignal; and a time delay between a transmission of a second signal and areception of the reflected second signal, wherein the second signal doesnot pass through the portion of the material.
 7. The system of claim 6,wherein the transmitter is configured to transmit the second signaltowards a portion of the reflector beyond an outer edge of the portionof the material.
 8. The system of claim 2, wherein the conveyor beltincludes a metal reinforcement, and wherein the transmitted signal isreflected off of the metal reinforcement before being reflected by thereflector.
 9. The system of claim 1, wherein a surface of the reflectorhas a radius of curvature configured to focus the reflected signal. 10.The system of claim 1, wherein the transmitter is configured to transmita respective signal through each of a plurality of portions of thematerial across a width of the material while the material is moving.11. A system for monitoring thickness uniformity, comprising: aplurality of transmitters on a first side of a conveyor belt, eachconfigured to transmit a respective signal through a respective portionof the conveyor belt while the conveyor belt is moving; a plurality ofantennas on a second side of the conveyor belt, each configured toreceive a respective one of the signals; and a computing deviceconfigured to determine a respective thickness of each portion of theconveyor belt based on a time delay between the transmission of thesignals and the reception of the signals.
 12. The system of claim 11,wherein the plurality of transmitters are arranged in a substantiallylinear arrangement and wherein the plurality of antennas are arranged ina substantially linear arrangement.
 13. The system of claim 11, whereineach of the antennas is located at a same distance from a respective oneof the transmitters.
 14. The system of claim 11, wherein the systemincludes a particular transmitter and a particular antenna locatedbeyond an edge of the conveyor belt, and wherein the computing device isconfigured to determine a reference distance between the plurality oftransmitters and the plurality of antennas using the particulartransmitter and the particular antenna.
 15. The system of claim 11,wherein the computing device is configured to individually activate eachof the plurality of transmitters at a respective time according to asequence.
 16. The system of claim 15, wherein the computing device isconfigured to deactivate an antenna adjacent to an antenna receiving asignal from an activated transmitter.
 17. A system for monitoringthickness uniformity, comprising: a plurality of antennas on a firstside of a conveyor belt; a transmitter on a second side of the conveyorbelt and separated from each of the plurality of antennas by a samedistance, wherein the transmitter is configured to transmit a signalthrough the conveyor belt at a first antenna of the plurality ofantennas at a first time while the conveyor belt is moving; and acomputing device configured to determine a thickness of the conveyorbelt between the transmitter and the first antenna based on a time delaybetween the transmission of the signal and the reception of the signalby the first antenna.
 18. The system of claim 17, wherein thetransmitter is configured to transmit the signal through the conveyorbelt at a second antenna of the plurality of antennas at a second timewhile the conveyor belt is moving, and wherein the computing device isconfigured to determine a thickness of the conveyor belt between thetransmitter and the second antenna based on a time delay between thetransmission of the signal and the reception of the signal by the secondantenna.
 19. The system of claim 18, wherein the first antenna isdeactivated while the transmitter is transmitting the signal through theconveyor belt at the second antenna.
 20. The system of claim 17, whereinthe computing device is configured to calibrate the system based on atime delay between a transmission of the signal and a reception of thesignal by an antenna of the plurality of antennas corresponding to anouter edge of the conveyor belt.